Mattermost Plugin: Lint GraphQL queries

[Dschoordsch]

          +1 it'd be nice to validate these strings so if the schema changes we're alerted https://www.loom.com/share/effc307dce5b42e5992e36c7e7c9aee6?sid=bf22c73b-cac7-48ba-a110-d79bb0a3cdc3

we could add this eslint plugin to do the work for us: https://the-guild.dev/graphql/eslint/docs

note:

i had to update my graphql.config.js file to the following:

module.exports = {
  schema: './packages/server/graphql/public/schema.graphql',
  documents: './packages/server/**/*'
}

Originally posted by @mattkrick in #10237 (comment)